Coupler Problem

Model Railroader Layouts and layout building
1

Hey,

I’ve got an Athern C44-9CW in BNSF colors with body mounted couplers. The freight cars I want have truck mounted couplers. I need open-top hoppers that are more hefty like the Bethgon Coalporter hoppers. If you have advice on how to change the couplers or a different hopper car set, please post.

Thanks, TheNarrowGaugeMan

2

If you have a wide enough minimum radius, this isn’t a problem. I mix body mount and talgo all the time, but we have minimum 30 inch radius on the club layout. Also, when you convert to Kadee couplers, even on talgo mounts, you eliminate most of the problem of the truck twisting sideways when the car is being pushed, when compared to the X2F couplers that used to come standard on all models.

If you decide to make the conversion, most cars with talgo mounted couplers can be converted to body mounts with a little bit of work. You can change out the trucks, or, if they’re good enough quality, cut off the coupler mount and use the Kadee box to mount the coupler per the Kadee instructions. I can give more specific instructions if you can tell us what cars you’re looking at (brand and model).

3

A lot depends on the radius of curve you plan to run these on. For 18-inch radius (in HO) you can use body-mount couplers up to about 50-foot long cars. After that, truck-mount will work better for you. Body-mounts will work better if your curves are all gentle, particularly when running in reverse, but they just can’t make it around tight curves.

I use Kadees for all my coupler needs, and I’ve never been the least bit disappointed.

4

Here are two pages that might help you make up your mind.

http://www.nmra.org/beginner/retrucking.html
http://www.nmra.org/beginner/couplers.html

5

Type of truck is also a factor. I have a lot of older Rivarossi passenger cars with truck-mounted horn-hook couplers. Other than a few head-end cars to couple up to locos (all my locos are knuckle-coupler equipped) I’ve never bothered changing them because they give me no trouble, even when pushing.

But those are all 6-wheel trucks, and I suspect because they’re longer with more wheels, they’re more resistant to the main problem with horn-hooks mounted on the trucks - sideways “shoving” of the trucks off the track when pushing.

I only had a few freight cars with horn-hooks and those I did replace. Pushing a 4-wheel truck with horn-hooks resulted in lots of derailments for me. I have not, to date, switched them to body-mount and the talgo trucks alone don’t seem to be a big issue, at least once KD’s are installed.

6

I am thinking about buying Gold Line Bethgon Coalporter Gondolas (if you get a monthly Walthers cataloge, it’s in the February issue on page 22). It looks like they have truck mounted couplers. The 9-44CW I was talking about is about 25cm or 10in long (a little more than 70 scale feet).I think that having body mounted couplers wasn’t the best thinking for those with small radius curves. The minimum radius curve for my layout is 18". That’s on the mainline. I use #4 turnouts. More info would be very helpful.

Thanks, TheNarrowGaugeMan

7

Your 9-44CW with body mount couplers is going to be at the heart of your problems. Since you are on the ragged edge of practicality, you are going to need a test program to get consistent operations with the big locomotive on 18" radius curves. Nothing is a given with a large locomotive on tight curves.

  1. Does the locomotive run acceptably on your curves by itself? If not, show-stopper. You will need a smaller locomotive or bigger curves.

  2. While stopped on the curve, do the couplers swing enough horizontally to get inside the outside rail on the curve? If not, you need longer shank couplers (Kadee makes them). You may also have to cut the opening in the pilot bigger. Or better yet would be truck-mounted couplers, but this would be a lot of work on a locomotive not designed for it.

  3. Once you have an acceptable coupler swing on the locomotive, and the locomotive operates on your curves, try hooking various cars to it. Take careful notes on which cars derail, and which don’t. Look for patterns in regard to truck or body mounted couplers, length of car, and length of coupler shank to see if you can generalize as to what is likely to work, and what isn’t.

  4. If you have a pattern or other test results that suggest the Coalporter Gondolas are going to work

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